Boron-Based Energetics

Navy SBIR 21.1 - Topic N211-026
NAVAIR - Naval Air Systems Command
Opens: January 14, 2021 - Closes: February 24, 2021 March 4, 2021 (12:00pm est)

N211-026 TITLE: Boron-Based Energetics

RT&L FOCUS AREA(S): General Warfighting Requirements

TECHNOLOGY AREA(S): Air Platforms; Materials / Processes; Weapons

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Determine a form of boron or a boron-based chemical pathway that leads to implementation of boron in energetic compounds, especially fuels (solid and liquid).

DESCRIPTION: Boron combustion tends to form species that are energetic dead-ends (the principal offender in this tendency is H-O-B-O). The use of a small amount of fluorine will tend to interrupt this result by breaking down the ceramic micro-encapsulation that molten boron exhibits. Current work to use boron in solid motors employs this technique, but the results depend on the application and test configuration. One potential reason for this is that this technique uses metallic (bulk) boron as a fuel, with the thermodynamic necessity of melting and evaporating the fuel prior to combustion.

Previous energetics work with boron indicated a necessity to incorporate the boron into potentially unstable compounds, the process of which increased the cost of the feedstock, and raised the likelihood of creating hazardous scenarios in the employment of the compound. Recent developments in the formation of boron allotropes have the potential to both lower feedstock cost and eliminate the need to use hazardous boron-bearing compounds.

A possible alternate combustion pathway begins with another form of boron, either as a compound that yields boron during combustion of another fuel, or an allotrope of boron that features an oxidizing element already attached to it in the desired ratio. Ideally, the attachment of oxidizing species to a boron allotrope would also yield the desired properties that would allow the compound to be successfully employed in a solid motor grain or in a petrochemical liquid suspension or solution.

This topic seeks to survey boron compounds and combustion pathways that enable complete boron combustion (to B2O3 or other oxidized species) in both solid fuel and liquid fuel uses. Solutions can be considered in both solid and liquid forms. Compound characterization will be completed using:

a. Liquid chromatograph-mass spectrometer (LCMS) to identify chemical species;

b. Gas chromatograph-mass spectrometer (GCMS) to identify chemical species;

c. Calorimetry to gauge the energetic potential;

d. Nuclear magnetic resonance (NMR) to characterize atomic arrangement of fuel species;

e. Fourier Transform Infrared (FTIR to characterize the evolved combustion species;

f. Laser ablation of a solid casting to characterize the evolved combustion species;

g. Combustors set to detect increased in thrust over neat-fuel combustion.

Tailoring the properties of the proposed materials will be undertaken after the determination of the material properties is made and an understanding of the needed property amendments can be described. When a suitable compound is achieved, the material will be tested in both solid and liquid forms. Laser ablation of a solid casting to characterize the evolved combustion species (captured as gases that are analyzed via GCMS) as well as calorimetry will provide the necessary data to evaluate the proposed use in a solid motor grain. Liquid combustion will be similarly sampled, using a calorimeter, a small-scale afterburner, and in a research-scale RDE. The combustors will provide the combustion gases to be analyzed by GCMS. Additionally, the combustors will be set to detect increases in thrust over neat-fuel combustion.

Work produced in Phase II may be classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by DoD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence Security Agency (DCSA), formerly the Defense Security Service (DSS). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this project as set forth by DCSA and NAVAIR in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advanced phases of this contract.

PHASE I: Survey boron compounds and combustion pathways that enable complete boron combustion (to B2O3 or other oxidized species) in both solid fuel and liquid fuel uses. Select the most promising compounds and pathways for further development in Phase II. Determine the technical feasibility of boron or a boron-based chemical pathway that leads to implementation of boron in energetic materials in a solid matrix (such as HTPB, or PBAN) for use in solid rocket motors, and in a hydrocarbon fuel (such as JP-10). Consideration of the materials for use in an afterburner or rotating detonation engine while also ensuring material characterization by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) to ensure full understanding of the material composition. Additional material characterization should include calorimetry to discover the energetic potential of the material, liquid chromatograph mass spectrometer (LMCS) to characterize the compound properties in a liquid or suspended state, and gas chromatograph mass spectrometer (GCMS) to characterize the compound properties in a gaseous state (pre-combusted or combusted). These characterizations should result in understanding the boron-compound�s composition, structure, bond energies, energy-release potential, reaction pathways, combustion precursors, and combustion products.

If exercised, the Phase I Option will include tailoring the properties of the proposed materials so that they can be eventually tested in both solid and liquid forms. As new materials, there are no relevant MILSPECs pertaining to their performance testing; however, the materials will fall under the energetic materials testing SOP requirements at NAWCWD China Lake.

PHASE II: Based on Phase I work, continue to develop and validate selected material by modeling of the combustion of the materials to provide predictive results for small-scale testing to be scaled up for larger combustors/larger solid motor grains, while identifying and testing cost-reduction techniques for feedstock and compound production. Successful test results in full scale representative hardware will be documented, as appropriate, and will lead to Phase III.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: A flying demonstrator will summarize progress to date and will collect data that will be of interest to mission requirements generators and technology stakeholders. An inexpensive flight platform will be selected for testing, a flight test will be executed, and the resulting data will be documented. Insertion of the technology into a Program of Record will be sought within PEO U&W. Production of the materials and techniques to obtain them will be pushed to full-scale, to allow economic production of the needed precursors, and finished fuels.

This technology has the potential to create commercial opportunity in supersonic and hypersonic transport, as well as for the space-launch industry.

REFERENCES:

  1. Lee, M. W., Jr. (2016, December 02). Catalyst-free polyhydroboration of dodecaborate yields highly photoluminescent ionic polyarylated clusters. Angewandte Chemie, 56(1), 138-142. https://doi.org/10.1002/anie.201608249
  2. Lee, M. W., Farha, O. K., Hawthorne, M. F., & Hansch, C. H. (2007, April 12). Alkoxy derivatives of dodecaborate: discrete nanomolecular ions with tunable pseudometallic properties. Angewandte Chemie, 46(17), 3018-3022. https://doi.org/10.1002/anie.200605126
  3. Goswami, L. N., Chakravarty, S., Lee, M. W., Jalisatgi, S. S., & Hawthorne, M. F. (2011, April 8). Extensions of the icosahedral closomer structure by using azide-alkyne click reactions. Angewandte Chemie, 50(20), 4689-4691. https://doi.org/10.1002/anie.201101066

KEYWORDS: boron; energetic; rocket fuel; turbine engine; afterburner; material characterization

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